Telescopic unlocking mechanism

ABSTRACT

A locking mechanism for an axially adjustable steering column includes a lock cam including a cam portion and a hub portion, wherein the cam portion and the hub portion are independent, separately formed components. The locking mechanism also includes a pin extending through the cam portion to permit the cam portion to pivot. The locking mechanism further includes a toothed portion formed on the cam portion for pivoting into engagement with teeth associated with the axially adjustable steering column in a locked position and out of engagement with the teeth in an unlocked position. The locking mechanism yet further includes an interface surface on the hub portion that includes at least one angled surface that interfaces with an adjustable lever and biases the cam portion from the locked position to the unlocked position.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims priority to U.S. Provisional PatentApplication No. 63/153,501, filed Feb. 25, 2021, the disclosure of whichis incorporated by reference herein in its entirety.

TECHNICAL FIELD

The following description relates to locking mechanisms, and moreparticularly, to a locking mechanism for a steering column assembly.

BACKGROUND

A vehicle, such as a car, truck, sport utility vehicle, crossover,mini-van, marine craft, aircraft, all-terrain vehicle, recreationalvehicle, or other suitable vehicles, include various steering systemschemes, for example, steer-by-wire and driver interface steering. Thesesteering system schemes typically include a steering column fortranslating steering input to an output that interacts with a steeringlinkage to ultimately cause the vehicle wheels (or other elements) toturn the vehicle. Some steering columns are axially adjustable betweenpositions to provide flexibility in the location of the hand wheel andfacilitate more comfortable driving positions for different sizes ofdrivers or autonomous driving capability. Many axially adjustablesteering columns further include rake actuators that permit tiltmovement around one or more pivot points. Telescopic steering columnswith both rake and axial movement can require a large amount of space tooperate in the underlying structure.

In addition to providing adjustability, axially adjustable steeringcolumn assemblies may also include a collapsible functionality thatprovides safety advantages during an energy absorption event. A lockingmechanism is oftentimes required to maintain a moveable portion of thesteering column assembly at a desired position after axial adjustment.One type of commonly used locking mechanism in the automotive industryis called a telescoping positive lock mechanism. When designing atelescoping positive lock mechanism, attention must be taken to allowfor proper column locked and unlocked conditions. The unlocked conditionmust ensure for the allowance of full telescopic/axial range ofadjustment. When the steering column assembly is locked, the steeringcolumn assembly must maintain a fixed telescopic/axial position whileunder normal vehicle operating conditions. However, during a collapseevent various measures may be implemented to ensure a required collapsecondition and/or range of motion while within a range applied load.

Accordingly, there is a continuing need to improve the operationalframework of locking mechanisms to improve upon packaging, loadrequirements, and dependability.

SUMMARY

According to one aspect of the disclosure, a locking mechanism for anaxially adjustable steering column includes a lock cam including a camportion and a hub portion, wherein the cam portion and the hub portionare independent, separately formed components. The locking mechanismalso includes a pin extending through the cam portion to permit the camportion to pivot. The locking mechanism further includes a toothedportion formed on the cam portion for pivoting into engagement withteeth associated with the axially adjustable steering column in a lockedposition and out of engagement with the teeth in an unlocked position.The locking mechanism yet further includes an interface surface on thehub portion that includes at least one angled surface that interfaceswith an adjustable lever and biases the cam portion from the lockedposition to the unlocked position.

According to another aspect of the disclosure, an axially adjustablesteering column assembly includes a first jacket and a second jacket,the second jacket axially moveable relative to the first jacket. Thesteering column assembly also includes an adjustable lever pivotablebetween a locked position and an unlocked position, the adjustable leverincluding a tab. The steering column assembly further includes a lockingmechanism located between the first jacket and the second jacket. Thelocking mechanism includes a cam portion including a toothed portion forpivoting into engagement with teeth associated with the first jacket inthe locked position and out of engagement with the teeth in the unlockedposition. The locking mechanism also includes a hub portion defining aninterface surface that includes at least one angled surface thatinterfaces with the tab and pushes the cam portion from the lockedposition to the unlocked position.

These and other aspects of the present disclosure are disclosed in thefollowing detailed description of the embodiments, the appended claims,and the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure is best understood from the following detaileddescription when read in conjunction with the accompanying drawings. Itis emphasized that, according to common practice, the various featuresof the drawings are not to-scale. On the contrary, the dimensions of thevarious features are arbitrarily expanded or reduced for clarity.

FIG. 1 generally illustrates a steering system including an adjustablesteering column assembly according to the principles of the presentdisclosure.

FIG. 2 generally illustrates a side view of the adjustable steeringcolumn assembly with an adjustment lever and a locking mechanism in alocked position.

FIG. 3 generally illustrates a side view of the adjustable steeringcolumn assembly with the adjustment lever and the locking mechanism inan unlocked position.

FIG. 4 generally illustrates an enlarged perspective view of theadjustment lever and the locking mechanism in the unlocked position.

FIG. 5 generally illustrates a sectional bottom view of the adjustmentlever and the locking mechanism in the unlocked position.

FIG. 6 generally illustrates a sectional bottom view of the adjustmentlever and the locking mechanism including an energy absorbing strap anda lock cam in the unlocked position such that the lock cam is spacedfrom the energy absorbing strap.

FIG. 7 generally illustrates a perspective view of the locking mechanismisolated from the steering column assembly.

FIG. 8 generally illustrates a perspective view that is opposite fromFIG. 7 and is of the locking mechanism isolated from the steering columnassembly.

FIG. 9 generally illustrates a perspective view of a locking mechanismin accordance with a second embodiment of the disclosure.

FIG. 10 generally illustrates a side view of the locking mechanism inaccordance with the second embodiment of the disclosure.

FIG. 11 is a side view of the locking mechanism according to anotheraspect of the disclosure.

DETAILED DESCRIPTION

The following discussion is directed to various embodiments of thedisclosure. Although one or more of these embodiments may be preferred,the embodiments disclosed should not be interpreted, or otherwise used,as limiting the scope of the disclosure, including the claims. Inaddition, one skilled in the art will understand that the followingdescription has broad application, and the discussion of any embodimentis meant only to be exemplary of that embodiment, and not intended tointimate that the scope of the disclosure, including the claims, islimited to that embodiment.

As described, a vehicle, such as a car, truck, sport utility vehicle,crossover, mini-van, marine craft, aircraft, all-terrain vehicle,recreational vehicle, or other suitable vehicles, include varioussteering system schemes, for example, steer-by-wire and driver interfacesteering. These steering system schemes typically include a steeringcolumn for translating steering input to an output that interacts with asteering linkage to ultimately cause the vehicle wheels (or otherelements) to turn the vehicle. Some steering columns are axiallyadjustable between positions to provide flexibility in the location ofthe hand wheel and facilitate more comfortable driving positions fordifferent sizes of drivers or autonomous driving capability. Manyaxially adjustable steering columns further include rake actuators thatpermit tilt movement around one or more pivot points. Telescopicsteering columns with both rake and axial movement can require a largeamount of space to operate in the underlying structure.

In addition to providing adjustability, axially adjustable steeringcolumn assemblies may also include a collapsible functionality thatprovides safety advantages during an energy absorption event. A lockingmechanism is oftentimes required to maintain a moveable portion of thesteering column assembly at a desired position after axial adjustment.One type of commonly used locking mechanism in the automotive industryis called a telescoping positive lock mechanism. When designing atelescoping positive lock mechanism, attention must be taken to allowfor proper column locked and unlocked conditions. The unlocked conditionmust ensure for the allowance of full telescopic/axial range ofadjustment. When the steering column assembly is locked, the steeringcolumn assembly must maintain a fixed telescopic/axial position whileunder normal vehicle operating conditions. However, during a collapseevent various measures may be implemented to ensure a required collapsecondition and/or range of motion while within a range applied load.

Referring now to the drawings, where the various embodiments are shownand described herein, without limiting same, FIGS. 1-11 illustrateembodiments of a steering column assembly that is axially adjustable andincludes a locking mechanism with improved dependability and otheroperational benefits. The axial adjustability can result from relativemovement between two or more jackets that permit axial movementtherebetween. For example, a first jacket and a second jacket move in arelative telescopic, sliding, or translational configuration.

Referring initially to FIG. 1 , a steering system 40 for a vehicle isgenerally illustrated according to the principles of the presentdisclosure. The vehicle may include any suitable vehicle, such as a car,a truck, a sport utility vehicle, a mini-van, a crossover, any otherpassenger vehicle, any suitable commercial vehicle, or any othersuitable vehicle. Moreover, principles of the present disclosure mayapply to other vehicles, such as planes, boats, trains, drones, or othersuitable vehicles.

The steering system 40 may be configured as a driver interface steeringsystem, an autonomous driving system, or a system that allows for bothdriver interface and autonomous steering. The steering system mayinclude an input device 42, such as a steering wheel, wherein a drivermay mechanically provide a steering input by turning the steering wheel.An airbag device 43 may be located on or near the input device 42. Asteering column assembly 44 extends along an axis from the input device42 to an output assembly 46. The output assembly 46 may include a pinionshaft assembly, an I-shaft, a cardan joint, steer-by-wire components orany other features conventionally located opposite the input device 42.The steering column assembly 44 may include at least two axiallyadjustable parts, for example, a first jacket 48 and a second jacket 50that are axially adjustable with respect to one another. The firstjacket 48 and the second jacket 50 may be alternatively configured asbrackets, rails, or other members that permit axial movementtherebetween. The axial movement may include sliding, telescopic,translating, and other axial movements. The steering column assembly 44may include a bracket 51 that at least partially connects the steeringcolumn to the vehicle 10. An adjustable lever 52 may be operablyconnected to one of the first jacket 48, the second jacket 50, or thebracket 51 to facilitate axial or tilting adjustment of the steeringcolumn assembly 44. In some embodiments, behavior of the adjustablelever 52 may be controlled via a control system 300 including a CPUunit. In some embodiments, behavior of the adjustable lever 52 may becontrolled manually.

The steering column assembly 44 is moveable between a range of positionsfrom an extended position to a retracted position. In the extendedposition, the first jacket 48 and second jacket 50 are moved axiallyaway from each other so that the input device 42 is located near anoperator of the vehicle. In the retracted position, the first jacket 48and second jacket 50 are moved axially towards each other so that theinput device 42 is located away from an operator of the vehicle. In someembodiments, the retracted position may correspond to stowing the inputdevice 42. For example, it may be beneficial to place the input device42 in a stowed location during autonomous driving. In some embodiments,the retracted position can be on the order of about 150 mm away from theextended position, such as at least 100 mm, or at least about 125 mmaway from the extended position. In some embodiments, the adjustablelever 52 effectuates axial movement between the first jacket 48 andsecond jacket 50 to adjustment between the extended position and theretracted position. In some embodiments, the adjustable lever 52effectuates rake or tilt movement of the steering column assembly 44.

A steering gear assembly 54 may connect to the output assembly 46 via asteering gear input shaft 56. The steering gear assembly 54 may beconfigured as a rack-and-pinion, a recirculating ball-type steeringgear, or any other types of steering gears associated with autonomousand driver-interface steering systems. The steering gear assembly 54 maythen connect to a driving axle 58 via an output shaft 60. The outputshaft 60 may include a pitman arm and sector gear or other traditionalcomponents. The output shaft 60 is operably connected to the steeringgear assembly 54 such that a rotation of the steering gear input shaft56 causes a responsive movement of the output shaft 60 and causes thedrive axel to turn the wheels 22.

FIG. 2 generally illustrates a side view of the adjustable steeringcolumn assembly 44 with the adjustment lever 52 and a locking mechanism62 in a locked position. The locking mechanism includes an energyabsorbing strap 64 and a lock cam 66 that are engaged in the lockedposition and spaced in the unlocked position. The adjustable lever 52includes a handle portion 68 that may include a U-shape and extends froma pivot end to a connection end that is connected to one of the jackets48, 50 (e.g. the second jacket 50) with a pin 70. The pin 70 may connectthe adjustable lever 52 to the bracket 51. The adjustable lever 52includes a tab 72 located between the pivot end and the connection endand is spaced adjacently to the lock cam 66. In operation, as theadjustable lever 52 is rotated from a locked position (FIG. 2 ), whereinthe steering column assembly 44 cannot be adjusted, to an unlockedposition (FIG. 3 ), wherein the steering column assembly can beadjusted, the tab 72 contacts the lock cam 66 and pushes the lock cam 66out of engagement with the energy absorbing strap 64. As such, theadjustable lever 52 does not directly interface with the energyabsorbing strap 64, but instead locks and unlocks the steering columnassembly 44 with the lock cam 66, which is a separate component. In theunlocked position, movement of the steering column assembly 44 may becompleted inhibited. The steering column assembly 44 may extend along anaxis A.

FIG. 3 generally illustrates a side view of the adjustable steeringcolumn assembly 44 with the adjustment lever 52 and the lockingmechanism 62 in an unlocked position such that the tab 72 is pivoted toa position that it is not pressing the lock cam 66 into the energyabsorbing strap 64. In the unlocked position, the steering columnassembly 44 may be expanded and retracted.

FIG. 4 generally illustrates the adjustment lever 52 and the lockingmechanism 62 in greater detail. The steering column assembly 44 is shownin the unlocked position. The lock cam 66 includes a hub portion 74 anda cam portion 76. It is to be understood that the hub portion 74 and thecam portion 76 are separate components. The hub portion 74 connects toan outer surface of the cam portion 76 or may be integral therewith. Thehub portion 74 includes an interface surface 75 that is geometricallyshaped and positioned to be pushed into and out of engagement with thetab 72. More particularly, the interface surface 75 may include a firstangled surface 78 that extends to an apex 80 (FIGS. 2 and 3 ) and asecond angled surface 82 (FIGS. 2 and 3 ) extending from the apex 80.The apex 80 may be triangularly shaped or rounded. The first angledsurface 78 and the second angled surface 82 may be on different planes.In operation, the tab 72 may be spaced from the first angled surface 78in the locked position (FIG. 2 ) and may pivot into contact with thefirst angled surface 78 as adjustable lever 72 is actuated (FIG. 3 ). Asthe tab 72 contacts the first angled surface 78, the lock cam 66 ispivoted away from the energy absorbing strap 64. In some embodiments,when the adjustable lever 52 is pivoted to the unlocked position, thetab 72 extends on or adjacent to the apex 80.

FIG. 5 generally illustrates a sectional bottom view of the adjustmentlever 52 and the locking mechanism 62 in the unlocked position. The camportion 76 includes a tail 84 and a toothed portion 86. The cam portion76 is operatively connected to a cam bracket 88 with a pin 90 that islocated between the tail 84 and the toothed portion 86. The lock cam 66is biased in the locked position by a torsion spring 92 that extendsabout the pin 90 and presses the tail 84 away from the axis. Inparticular, the cam portion 76 defines an aperture that the pin 90extends through and the hub portion 74 also defines an aperture that thepin 90 extends through. Therefore, the hub portion 74 and the camportion 76 are each pivotable about the pin 90, i.e., the same axis. Oneend of the torsion spring 92 attaches to a strap cover 99 which ispermanently fixed to the lower jacket 50. The torsion spring 92 wrapsaround the pin 90 and pushes down on the toothed portion 86 of the camportion 76, thus pushing the toothed portion 86 towards the axis A andinto engagement with the teeth 96 on the energy absorbing strap 64. Thehub portion 74 may include a recess 93 for locating the tail 84. Theenergy absorbing strap 64 may include a first straight portion 94defining a series of teeth 96 that are intermeshed with the toothportion 86 in the locked position. The energy absorbing strap 64 mayfurther include a curved portion 98 that enters into an opening of thesecond jacket 50 to a second straight portion 100 that connects to thefirst jacket 48. During an impact event, the energy absorbing strap 64dissipates at least some of the kinetic energy of collapsing firstjacket 48 and the second jacket 50 via relative pulling of the firststraight portion 94 and the second straight portion 100 andconsequential rolling of the curved portion 98. In some embodiments, theteeth 96 may be located directly on the first jacket 48 or othercomponents connected therewith.

FIG. 6 generally illustrates a sectional bottom view of the adjustmentlever 52 and the locking mechanism 62 including the energy absorbingstrap 64 and a lock cam 66 in the unlocked position such that the lockcam 66 is spaced from the energy absorbing strap 64.

FIG. 7 generally illustrates a perspective view of the locking mechanism62 isolated from the steering column assembly 44. The energy absorbingstrap 64 may include an aperture 102 for facilitating connection to thefirst jacket 48. FIG. 8 generally illustrates a perspective view that isopposite from FIG. 7 and is of the locking mechanism 62 isolated fromthe steering column assembly 44. The energy absorbing strap 64 mayinclude a strap tab 104 for facilitating connection to the second jacket50.

FIG. 9 generally illustrates a perspective view of a locking mechanism162 in accordance with a second embodiment of the disclosure. Unlessotherwise indicated, the second embodiment may share all of the samefeatures, elements, and functionalities of the first embodiment. Similarelements are numbered under the same convention as the first embodimentwith a number “1” placed before. The locking mechanism 162 is similar tothe first embodiment, however includes a modified hub portion 174 andcam portion 176. More particularly, the cam portion 176 includes asmaller tail portion 184 (FIG. 10 ). In some embodiments a spring 192directly biases the toothed portion 176 towards an energy absorptionstrap. The hub portion 174 further defines an insertion recess 193 forplacement of the cam portion 176 therein. The cam portion 176 mayfriction fit into the insertion recess 193 and be connected thereto viawelding or other methodologies. In some embodiments, the cam portion 176is formed via stamping before connection to the hub portion 174. FIG. 10generally illustrates a side view of the locking mechanism 162 inaccordance with the second embodiment of the disclosure.

FIG. 11 generally illustrates a side view of a locking mechanism 262 inaccordance with a third embodiment of the disclosure. Unless otherwiseindicated, the third embodiment may share all of the same features,elements, and functionalities of the first and second embodiments.Similar elements are numbered under the same convention as the previousembodiments with a number “2” placed before. The locking mechanism 262is similar to the above-described embodiments, however includes amodified hub portion 274 and cam portion 276. More particularly, the camportion 276 includes a smaller tail portion 284 that is disposed withina cavity 270 of the hub portion 274. Additionally, the cam portion 276includes a tab 275 also disposed within a recess 277 of the hub portion274. As with the prior embodiments, the toothed portion 276 is biasedtowards the energy absorption strap 264.

The above-described embodiments, implementations, and aspects have beendescribed in order to allow easy understanding of the present disclosureand do not limit the present disclosure. On the contrary, the disclosureis intended to cover various modifications and equivalent arrangementsincluded within the scope of the appended claims, which scope is to beaccorded the broadest interpretation to encompass all such modificationsand equivalent structure as is permitted under the law.

What is claimed is:
 1. A locking mechanism for an axially adjustablesteering column comprising: a lock cam including a cam portion and a hubportion, wherein the cam portion and the hub portion are independent,separately formed components; a pin extending through the cam portion topermit the cam portion to pivot; a toothed portion formed on the camportion for pivoting into engagement with teeth associated with theaxially adjustable steering column in a locked position and out ofengagement with the teeth in an unlocked position; and an interfacesurface on the hub portion that includes at least one angled surfacethat interfaces with an adjustable lever and biases the cam portion fromthe locked position to the unlocked position.
 2. The locking mechanismof claim 1, wherein the teeth associated with the axially adjustablesteering column includes teeth located on an energy absorption strapoperatively coupled to the axially adjustable steering column.
 3. Thelocking mechanism of claim 1, wherein the pin extends through the hubportion to permit the hub portion to pivot.
 4. The locking mechanism ofclaim 1, further comprising a biasing member in contact with the camportion to rotatably bias the cam portion into the locked position. 5.The locking mechanism of claim 4, wherein the biasing member comprises atorsion spring.
 6. The locking mechanism of claim 5, wherein the torsionspring at least partially surrounds the pin.
 7. The locking mechanism ofclaim 4, wherein the cam portion includes a tail portion in contact witha leg of the hub portion, wherein rotation of the hub portion biases thecam portion with the leg toward the unlocked position by overcoming abiasing force by the biasing member.
 8. The locking mechanism of claim7, wherein the tail portion is disposed within a recess defined by thehub portion.
 9. The locking mechanism of claim 4, wherein the biasingmember is fixed at an end of the biasing member to an energy absorbingstrap cover.
 10. An axially adjustable steering column assemblycomprising: a first jacket and a second jacket, the second jacketaxially moveable relative to the first jacket; an adjustable leverpivotable between a locked position and an unlocked position, theadjustable lever including a tab; a locking mechanism located betweenthe first jacket and the second jacket, the locking mechanismcomprising: a cam portion including a toothed portion for pivoting intoengagement with teeth associated with the first jacket in the lockedposition and out of engagement with the teeth in the unlocked position;and a hub portion defining an interface surface that includes at leastone angled surface that interfaces with the tab and pushes the camportion from the locked position to the unlocked position.
 11. Theaxially adjustable steering column assembly of claim 10, wherein theteeth associated with the axially adjustable steering column includesteeth located on an energy absorption strap operatively coupled to theaxially adjustable steering column.
 12. The axially adjustable steeringcolumn assembly of claim 10, wherein the cam portion and the hub portionare independent, separately formed components.
 13. The axiallyadjustable steering column assembly of claim 10, wherein the pin extendsthrough the hub portion to permit the hub portion to pivot.
 14. Theaxially adjustable steering column assembly of claim 10, furthercomprising a biasing member in contact with the cam portion to rotatablybias the cam portion into the locked position.
 15. The axiallyadjustable steering column assembly of claim 14, wherein the biasingmember comprises a torsion spring.
 16. The axially adjustable steeringcolumn assembly of claim 15, wherein the torsion spring at leastpartially surrounds the pin.
 17. The axially adjustable steering columnassembly of claim 14, wherein the cam portion includes a tail portion incontact with a leg of the hub portion, wherein rotation of the hubportion biases the cam portion with the leg toward the unlocked positionby overcoming a biasing force by the biasing member.
 18. The axiallyadjustable steering column assembly of claim 17, wherein the tailportion is disposed within a recess defined by the hub portion.
 19. Theaxially adjustable steering column assembly of claim 14, wherein thebiasing member is fixed at an end of the biasing member to an energyabsorbing strap cover.